Oct. 5, 2011 -- Steve Jobs, the visionary co-founder of Apple Inc. who revolutionized the way we use technology, died today after fighting advanced pancreatic cancer since 2004. The death was announced by the company he helped found.

"Apple has lost a visionary and creative genius, and the world has lost an amazing human being," Apple stated in a note on its web site. "Those of us who have been fortunate enough to know and work with Steve have lost a dear friend and an inspiring mentor. Steve leaves behind a company that only he could have built, and his spirit will forever be the foundation of Apple."

Unlike many famous people diagnosed with cancer or other fatal illnesses, Jobs revealed few details about his health after he was diagnosed with pancreatic cancer.

That was also true when he resigned from the company in August 2011. Jobs' shed little insight on his condition in this excerpt from his letter to the Apple Board of Directors:

"I have always said if there ever came a day when I could no longer meet my duties and expectations as Apple's CEO, I would be the first to let you know. Unfortunately, that day has come.

I hereby resign as CEO of Apple. I would like to serve, if the Board sees fit, as Chairman of the Board, director and Apple employee."

He was, however, willing to talk about death, as he did in this 2005 commencement speech at Stanford University. He shared his relief at the time that he was diagnosed with a rare form of pancreatic cancer -- one did not mean an immediate death sentence. Yet he was realistic about his future:

"Remembering that I'll be dead soon is the most important tool I've ever encountered to help me make the big choices in life. Because almost everything -- all external expectations, all pride, all fear of embarrassment or failure -- these things just fall away in the face of death, leaving only what is truly important. Remembering that you are going to die is the best way I know to avoid the trap of thinking you have something to lose. You are already naked. There is no reason not to follow your heart."

Legendary Career

In his nearly four-decade career, Jobs oversaw the development of some of the most iconic tech products of the past half century.

He co-founded Apple Computer Inc. in 1976. Based in Cupertino, Calif., the company developed one of the first commercially successful personal computers, the Apple II. Less than 10 years after its founding, though, Apple's business had lost its momentum, and, in 1985, Jobs was forced to resign.

A year later, Jobs helped found Pixar, the independent animation studio that produced Toy Story and its two sequels, Monsters Inc., Ratatouille, and a host of others Academy Award-winning computer-animated films.

Jobs returned to Apple in 1996. The following year he was named CEO, a position he resigned in August 2011.

Back to Apple

During his second tenure at Apple, the company introduced the iPod, the iPhone, and, most recently, the iPad. The popularity of each propelled Apple into its current position as one of the world's most valuable technology companies.

Meanwhile, its Macintosh line of personal computers has, over the past several years, transformed the company from an also-ran to a top seller in the PC market.

But as Jobs was reviving Apple, his own health was suffering.

Jobs' Cancer

In 2004, Jobs was diagnosed with a rare form of cancer when a neuroendocrine tumor was discovered in his pancreas. Such tumors occur in fewer than one in 100,000 people per year, far fewer than other types of pancreatic cancer.

The distinction between types of pancreatic cancer is an important one. Whereas the most common form of pancreatic cancer is quite aggressive and deadly, neuroendocrine pancreatic cancer typically progresses slowly and is often treatable.

"Neuroendocrine cancer has a much better prognosis," says Rodney Pommier, MD, a surgeon at Oregon Health and Sciences University and an expert in neuroendocrine cancer. Pommier did not participate in Jobs's care.

Jobs had surgery in 2004 to remove the tumor, after which he returned to work. Five years later, though, he took another medical leave of absence from Apple. This time, he underwent a liver transplant at Methodist University Hospital in Memphis.

Throughout his illness, Jobs preferred privacy over public disclosure of the details of his condition, and the reason for the liver transplant was never disclosed. There was speculation at the time that it was done because his cancer had spread to his liver.